Plasma ignition system for internal combustion engine

A plasma ignition system for a multicylinder internal combustion engine having a high compression ratio, each cylinder being provided with a plasma ignition plug, which comprises:

• (a) a plasma ignition energy generating circuit which generates plasma ignition energy, said circuit having (1) at least one capacitor which charges to a predetermined high DC voltage and operatively discharges the predetermined high DC voltage into said plasma ignition plugs according to a predetermined ignition order and (2) at least one inductor means, connected between said capacitor and each of the plasma ignition plugs, which operatively receives the predetermined high DC voltage discharged by said capacitor;
• (b) an oscillation device having at least one oscillator means which operatively generates a high-frequency oscillation voltage;
• and
• (c) means connected to said plasma ignition energy generating circuit and oscillation device for controlling the discharge of said capacitor so as to apply the DC voltage within said capacitor to one of the plasma ignition plugs at a predetermined ignition timing of the corresponding engine cylinder according to a predetermined ignition order and, at the same time, for actuating said oscillation device to apply the high-frequency oscillation voltage to one of the remaining plasma ignition plugs installed within the engine cylinder which is substantially in the start of compression stroke until at least the plasma ignition is started at the remaining plasma ignition plug by subsequent application of said DC voltage whereby a complete combustion of air-fuel mixture supplied into the engine cylinders can be achieved for a high-compression engine.